Hydraulic lift trailer



Aug. 11, 1953 Filed July l2, 1949 J` C. FALKENHAGEN HYDRAULIC LIFT TRAILER 6 Sheetjs-Sheet l u Il! ,l 7611 E il? I f l@ f 72 5 y 'ZZ mil) I|||| Z j E11 l"l 3 l' j \J if @j l y; LL"""' WH JJ 5 4 Z9 m 52 J6 I 5J I 54 U Aug. 1l, 1953 Filed July 12, 1949 J. c. FALKENHAGEN 2,648,546

HYDRAULIC LIFT TRAILER 6 Sheets-Sheet 2 N L- r11/wrs a f5 Zien/Fey er;

Aug. l1, 1953 J. c. FALKENHAGEN 2,648,546

HYDRAULIC LIFT TRAILER Filed July 12, 1949 a sheets-sheet s Aug. 11, 1953 J. c. FALKENHAGEN 2,648,546

HYDRAULIC LIFT TRAILER Filed July l2, 1949 6 Sheets-Sheet 4 Allg. l1, 1953 J. c. FALKENHAGEN 2,648,546

HYDRAULIC LIFT TRAILER Filed July l2, 1949 8 Shee'cs-Sheet 5 Aug. 11, 1953 J. c. FALKENHAGl-:N 2,648,546

HYDRAULIC LIFT TRAILER Filed July. l2, 1949 6 Sheets-Sheet 6 Patented ug. 171, 1.9153

UNITED STATES PATENT OFFICE HYDRAULIC LIFT TRAILER John C. Falkenhagen, Chicago, Ill., assignor to George L. Nadell, Chicago, Ill.

Application July 12, 1949, Serial No. 104,275

8 Claims.

My invention relates to hydraulic lift trailers and more particularly to a unit of this type which may be coupled for load transport to any type of towing vehicle, including passenger cars.

One object of the invention is to devise a trailer equipped with a load carrying body that may be hydraulically raised to a transporting position between the wheels or dropped to a substantially ground level position for discharging or receiving a load.

A further object is to provide a two wheel trailer of the character indicated which includes a stabilizing cable system that equalizes the application and release of pressure to the lifting and dropping mechanism on opposite sides of the trailer body and prevents tilting of the body while being raised or dropped.

A further object is to devise a trailer as above characterized whose body is carried on the usual springs during road transport and in which means is provided for disengaging the body from the springs to enable lowering of the body.

A further object is to provide a two wheel trailer as above indicated which includes stub axles whereby the body may be moved between the wheels from one limiting position to another.-

These and further objects of the invention will be set forth in the following specification, reference being had to the accompanying drawings, and the novel means by which said objects are effectuated will be definitely pointed out in the claims.

In the drawings:

Figs. 1 and 2 are side elevations of the trailer showing, respectively, the body thereof in raised or load transporting position and in lowered or load discharging or receiving position.

Fig. 3 is a top plan View of the trailer chassis with the body removed.

Fig. 4 is a side elevation, partly in section, of the lift mechanism and spring suspension on the left side of the chassis, considered with respect to its normal direction of movement over a roadway. the body being removed and the near wheel and axle being shown in dot-dash lines, all as ,I

taken along the line 4-4 in Fig. 5.

Fig. 5 is a section -along the line 5-5 in Fig. 4.

Fig. 6 is a perspective, schematic view of the stabilizing cable system as viewed in the direction of the arrow 6 in Fig. 4.

Fig. 7 is a fragmentary, sectional view of the releasing handle and latch therefor which controls the positions of the yoke bars that rest on the ends of and transfer the body load to the semi-elliptic springs.

Fig. 8 is a perspective view of one end of a yoke bar.

Figs. 9 and 10 are sections respectively taken along the lines 9 9 and III-I0 in Fig. 3.

Fig. 11 is an enlarged view, partly in section, of the upper part or right side of the chassis as it appears in Fig. 3.

Fig. 12 is an enlarged, fragmentary, sectional view of the lower end of the lift mechanism as it appears in Fig. 4.

Fig. 13 is an elevation, partly in section, of the lift pump as viewed in the direction of the arrow I3 in Fig. 3.

Fig. 14 is a side elevation of the pump, partly in section, looking in the direction of the arrow I4 in Fig. 13, and showing the throttle control which regulates the lowering speed of the body.

Fig. 15 is a fragmentary section along the line I5-I5 in Fig. 14 showing further details of the throttle control.

Figs. 16 and 17 are elevations, partly in section, corresponding, respectively, to Figs. 4 and 5, but showing a moded arrangement which employs coil or helical instead of semi-elliptic springs.

Figs. 18 and 19 are sections along the lines I 8-I8 and Ill-I9, respectively, in Fig. 16.

Figs. 20, 2l and 22 are side, top and perspective views of the spring saddle for transferring the body load to the coil springs.

Referring to Figs. 1 to 3, inclusive, the trailer comprises a chassis III having attached thereto an appropriate body II. The chassis is formed as a generally rectangular fr-ame including side members I2I2, front and rear members I3 and I4, respectively, and V-related members I5-I5 which extend forwardly of the front member I3, the spaced ends of the members I5 being fastened respectively to the side members I2 and at the junction of the members I5 is fastened .a hitch, generally indicated by the numeral I6, for connecting the trailer to a towing vehicle.

A-s shown in Figs. 4, 5 and 11, there is attached to the outside of each side member I2 the lower end of a channel upright I'I which extends upwardly therefrom along the side Walls of the body II. The upright I'I includes a web IB-and spaced wings I9 and at its upper end is closed by an abutment plate 20 which extends transversely of and outwardly from the web I8 beyond the wings I9 for a purpose persently explained. The lower end of the upright I'I is closed by a plate 2l which is secured to the underside of the adjacent side member I 2 and positioned betweenA the wings I9 is a pair of spaced guide rods 22 whose upper ends are fastened to an angle `23 which in turn is connected to the upright web i8. The lower end of each rod 22 extends through an aperture 2d in the plate 2l and rests on a plate 25 which is secured to the plate 2|. Hence, the rods 22 are rigidly connected to the associated upright I1 and move therewith, along with the chassis I and body l1 when the latter are raised and lowered as presently described.

Each rod 22 is slidable through upper and lower lugs 26-26 carried by the inside wall 21 of .a vertical cage 28 whose outside wall 29 is parallel to the wall 21 and connected thereto by spaced struts 30. A stud axle has its inner end secured to the outer plate 29, extends outwardly therefrom and journaled thereon in an appropriate manner is a supporting wheel 32. The lower end of the cage 28 is closed by a plate 33 on which rests the central part of a semi-elliptic spring 34 which extends lengthwise of thel chassis, the spring being clamped between the plate and an overlying block 3,5 by means of a pair of spaced U-bolts 336-36. Y

Resting on the ends of each spring are the ends of forward and rear yoke bars 31 and 38 which extend transversely of the chassis with the last named ends projecting outwardly oi the side members l2, all respectively (see Figs. 3 and 10). The yoke bars 31 and 38 extend beneath and in contact with the side members i2 and serve to transmit the chassis load to the springs 3H.. Further, the bars 31 and 38 areconditioned for movement in opposite directions longitudinally of the chassis to clear the ends of the springs and so enable the chassis to be raised or lowered. During these movements, the bars 31 and 38 operate between the under sides oi the side members l2 andthe offset portions of guide strips 39. which are secured to the members l2,I the extremities of the offset portions serving to limit the bar movements. In the raised or load supporting position of the chassis as illustrated in Figs'. 3 and 4, the bars 31 and 38 are heldin the -retracted position shown by springs 40- and di, respectively, the inner ends of the springs being attached to chassis cross pieces i2-i2 and the outer ends to the bars 31 and 38, respectively. For the purpose of further separating the bars 31 and 3B so that their ends will clear the ends o the springs 3d, the bar 31 has fastened thereto in symmetrical location with respect to the longitudinal center line of the chassis the ends of ay cable 43 whose central portion is connected to a cable.V 44. that extends forwardly through the iront chassis member i3y for attachment to. an operating handle 45 (see Fig. '7) that is intermediately pivoted at 46 on the front end of thek body l l. To insure simultaneous movement of the rear yoke bar 35, a pair of cables. l1-d1 have their forward ends secured to the bar 31, thence extend rearwardly of the chassis and around pulleys i8 mounted on the rear member ill, and thence forwardly for connection to the yoke bar 38. Hence, when. the handle 5 is rocked clockwise from the position shown in Fig. 7, the ends of the bars 31 and 33- will be simultaneously moved clear of the ends of the springs 34 and the chassisr is, then conditioned for vertical movement byv means presently described. The bars 31 and 38- are held in their further spread positions by engaging a latch link 49' carried by the body Ii with a notch 50 providedin the handle 45.

The chassis is hydraulically raised to the transporting position shown in Fig. 1 and gravity lowered under hydraulic control by instrumentalities which will now be described.

Mounted on the V-related members l5 forwardly of the body I I and hence easily accessible by the operator is a single acting, lift pump 5I (see Figs. 1, 2 and 3) which is more particularly illustrated in Figs. 13, 14 and 15 to which reference will now be made.

The pump 5l comprises a casing 52 which serves as a reservoir for the working liquid, usually an oil, and mounted on the top of the casing is a cylinder 53 in which is reciprooable a piston 54 whose upper end projects beyond the adjacent end of the cylinder for pivotal connection to an intermediate part of an actuating handle 55. One end o the handle 55 is pivotally connected to one end of a link 56 whose opposite end is pivoted to an ear 51 projecting from the cylinder 53. The lower end of the cylinder bore is enlarged as at 5E and depending from the enlarged bore within the casing 52 is a pipe 59. Entrance of oil from the casing into the pipe is controlled in the usual manner by ay freely movable ball 63.

The upper end of the bore 53. communicates through a lateral passage 3i with a chamber 62, and flow in one direction from the passage tothe chamber is freely permitted by a ball 53 which denies ow in the opposite direction, the ball 5,3. engaging a valve seat formed atv the junction ot the passage and chamber. Hence, when the pis.- ton is raised from the position shown in Fig. 13 the ball t@ is unseated and oil flows, upwardly into. the bore 5S. When the piston 54; is moved downwardly, the ball 60 is seated and oil under pres,- sure is forced into the chamber 52 and thencev through a pipe 6,4 to actuate a chassis. raising` piston presently described.

As already indicated, the chassis is gravity lowered under hydraulic control and duringt-his operation, the oil returns through the pipe 6d to the chamber 62 to thereby seatk the `pall S3 and` prevent return of the oil to the casing through the passage 6I. A throttling control onl thev oilV return is provided by a manually controlled valve 65 which regulates thev oil flow` through a passage l` that provides.l communication betweentl'ie chamber 82, and a. passage 6 1; leading to the cas.- ing 52. The pump 5l; isa. c0mmercialldfrl obtainable article and per se does. not iorm any part. of the present invention.

As indicated in Fig. 3, the pipe 54y extends` rearwardly of the chassis for connection to branch. pipes 687-68, each of which connects with one end of a passage 69 (see Fig. 12) in a block 35. above the associated spring 36 the opposite end of thepassage communicating with the lower end of a cylinder; 1e which is welded to the block and extends upwardly within the cageV 28I (see Figs. -i and 5). Slidable within the cylinder 10 is a piston 1i whose upper end projects beyond the corresponding end o the cylinder and in both chassis raised and lowered positions occupies the position. about las shown in Figs. 5Y and 12L In the operation ofA the trailer, if it is desired; to drop the chassis from the position shown in Fig. 1 to that indicated in Fig. 2 where the chassis rests on the ground, the valve 65 is closed. and the pump 5l is actuated to raise the pistonv 1i until it engages the abutment piate 29: and raises thel uprights I1 and the connected body and' chassis sufciently to raise the ends of* theyoke bars 3.1 and. 38 above the ends of the springs 3Q. rlhe handle 45, which is conveniently located close tothe pump is then rocked clockwise and latchedby the link 49A to therebyl move the Aends of the yoke bars 31 and 3 beyond and clear of the ends ofz the springs 34. The valve 35 is. then openedslightly and the chassis is lowered by gravity, the abutment plates 29 pushing the pistons 1I against the throttling control exercised by the valve 65. The chassis therefore descends slowly and contacts the ground substantially without shock. After the chassis reaches its lowermost position, the pistons 1I continue to drop of their own weight until they about reach the position shown in Fig. 12.

To raise the chassis from its ground position, the valve 65 is closed and the pump 5| is actuated to again move the pistons 1I upwardly to contact the abutment plates 29. The chassis is accordingly moved upwardly to a position slightly above that shown in Fig. 1, in which position the ends of the yoke bars 31 and 38 are at elevations above the ends of the springs 34, but displaced therefrom. Thereupon, the handle 45 is unlatched and rocked to shift the yoke bars 31 and 38 so that their ends are immediately above the ends of the springs 34, the valve 65 is opened slightly, and the chassis slowly descends until it rests on the leaf springs 34. The pistons 1I continue downward until they approximately reach the positions shown in Figs. 5 and l2.

From the foregoing, it will be apparent that the chassis assembly is movable in vertical directions relative to thel cage assemblies which carry the wheels, the sole connections between these parts during such movements being provided by the guide rods 22 and lugs 26. Further, these rods and lugs provide adequate structuralconnections between the chassis and cage assemblies so that the wheels are maintained in proper rolling relation to the ground. When uncoupled from the towing vehicle, the forward end of the chassis may be supported by appropriately positioning a stem 12 that is threaded through a plate 13 carried by the members I5.

An important feature of the invention resides in the arrangement for insuring that the chassis will, during its vertical movements, move freely without binding between the guide rods 22 and lugs 26. Such binding might occur, in View of the rise of the single acting pump, if there were any inequality in the delivery to or return of oil from the cylinders 10. Under such conditions either piston 1I would move up or down, as the case may be, faster than the other piston 1I. Therefore, the uprights I1 are tied together by a dual cable system which acts as a stabilizing factor, decreases the tendency of the chassis to cant longitudinally or transversely, and serves to substantially equalize the oil pressure in the cylinders 10.

Referring to Figs. 3, 4, 5, 6 and 9, one end of a cable 14 is xed to a bracket 15 that is attached to the forward part of that cage 28 which is on the left hand side of the chassis, considered with respect to its normal direction of movement along a roadway. The cable 14 passes upwardly and around a pulley 16 mounted on the forward part of the adjacent upright I1, thence downwardly and around a pulley 11 mounted on the adjacent side member I2, thence transversely of the chassis where it passes around a pulley 18 secured to the side member I2 on the right side of the chassis and thence upwardly for attachment to a bracket 19, similar to the bracket 15, mounted on the forward part of the adjacent cage 28.

Rearwardly of the uprights I1, there is a similar cable system, but reversed in position as follows: One end of a cable 80 is fast to a bracket 8l on the left side cage 28, thence passes downwardly around a pulley 82 carried by the ad jacent side member I2, thence transversely of the chassis where it passes around a pulleyY 83 secured to the right side member I2, thence upwardly and around a pulley 84 that is carried by the rear side of the adjacent upright I1, and thence downwardly for attachment to a bracket 85 carried by the rear end of the right side cage 28.

The schematic relation of the parts just described is best shown in Fig. 6. The brackets, 15, 19, 8I and 85 stand at the same elevation and are always Xed in position since they are carried by the cages 28, while the respective pulleys, being carried by the chassis assembly,v change positions with respect to the brackets during vertical movements of the chassis. The cables 14 and 80 are taut at all times.

In Figs. 16 to 22, inclusive, is illustrated a modified design in which helical or coil springs provide the resilient support for the chassis as a substitute for the semi-elliptic springs. Where parts are identical with those already described, they are identied by like numerals.

Each stub axle 3i projects from the outer wall 86 of a cage 81 which includes an inner wall 83, end walls 89-39, and a bottom wall 90. As indicated in Fig. 17, the inner wall 88 extends above the top edge of the outer wall 86 and has aflixed thereto upper and lower lugs 9I-9I, similar to the lugs 26, and through which are slidable the guide rods 22. A pair of coil springs 92-92 are vertically positioned within the cage 81 in spaced relation and with their lower ends resting on the bottom wall 99. The upper ends of the springs abut a spring cap 93 which is provided with a pair of depending legs 94-94 which, respectively, have sliding contact with the outer surfaces of the cage end walls 89-89. The cap 93 and legs 94 act as a spring saddle. Extending laterally from each leg 94 longitudinally of the chassis is a pad 95, the forward pads 95 having resting thereon the ends of the yoke bar 31 during periods of load transport, while the ends of the yoke bar 38 rest on the other pads 95. Auxiliary guide and retaining rods 96-96 may beA lower ends of provided within the cage 81, the these rods being carried by the bottom plate 99 and extending upwardly within the springs 912v and slidably through the spring cap 93.

A block 91 is carried by the inner side of the lower cage plate 99 and includes a passage 98 for respectively connecting with one of the branch oil pipes 68 and the lower end of'a cylinder 99 which is positioned between the springs 92 and in which is reciprocable a piston 99. The hydraulic actuation and control of their modification is identical with that described for the leaf spring design, as is also the control of the yoke 1lioars 31 and 3B and the stabilizing cable sys- In both of the foregoing designs, it will be noted that the trailer comprises a plurality of assemblies including a frame assembly which is composed of the side, front and rear members I2, I3 and I4, respectively, and all parts carried thereby, and a pair of wheel assemblies, each of which is composed of a wheel 32, the associated cages 28 or 82', and all parts carried by the respective cages. Generally speaking, the frame assembly is movable relative to the wheel assemblies in vertical directions.

Further, the frame assembly may be stopped during descent from the spring supported position at any point short of groundcontact by closing the throttle valve 65` and the'frame is then nazis-,54e

supported onthepistonstl. Under? someVv con'- ditions, the pistons-Tl' may drop to' the bottomv oi? tlie' cylinders TU andthe distance between the topof eacli piston` Hl in the retracted position and the associated plate 21!Y may be varied as desired. The cables 154 and lmay be replaced by suitable chains ort any' appropriate flexible members.-

I claim: y

1. A-liit trailer c'or-iipris'ing-r a trame assembly, supporting wheel assemblies on opposite' sides ofthe frame assembly, ccacting formations'- on the frame and wiieel assemblies providing for relative guided-fV movements ofthe frame assembly, spring means carried by each Wheel assembly, barson tbe frame assembly movable in one direc'- tion to restionthev spring means to" support theV frame assembly thereon'- and in tbe opposite direction to clear the spring means and permit descentof the traine assembly, and a hydraulic system-includinga pump", a cylinder' carried by each wheel'- assembly, a piston movable upwardly in the cylinderV to engage-tire frame assembly and raise the same to transporting positiony and` tlfirottley means for controlling the gravity descent of theA trame assembly when the bars are ireedlof the spring means and the pump is' not operating; y

2. A liittrailer comprising a fra-me assembly, supporting wheel assemblies `on opposite sides of tl'iev frame assembly, coacting formations onI the framel and Wheel assemblies providing for relativeI guided movements of the frame' assembly, a-sernilelliptic spring carried by each Wheel assembly, bars en the frame assembly movable inl` one direction to rest orithe endsl of the springs toV support` theframev assembly thereon' and in` tlie opposite'v direct-ioni to cl'e'ar the springs andpermit' descent of tliefraine* assembly, and a' hydrauli'e system includinga pump, a cylinder carried by eachI wlieel4 assembly, a piston movable' upwardly in the cylinder to engagetiie' frame assembly and raise the sameto transporting position,` and throttlevmeans'for controlling the'gravity descent of the frame assembly when tbebars are treed of the springs and the pump is notV operating.

3. A lift* trailer comprising a` frame assembly, supporting wheel assemblies on opposite' sides of the frame assembly, coa-ating formations on the frame andz Wheel assemblies providing for relative guided movements of' tliev frame assembly, coil springs'carriedE by each wiieel assembly, bars onthe frameassembly movable in one direction to rest on tliesprings'tol support' the' frame assembl'y thereon and'l in the opposite. direction to' clear tlies-p-rings andp'ermit descent of'tlieframe assembly, and4 a hydraulic system including a pump, a cylinder carriedby each wheel assembly; a pistonmovable" up-wardly in' the cylinder to engage the frame and raise the same to transporting' position; and throttle means for controlling tlieY gravity descentV of the frame assembly wlie'nthe' bars are freedirom the springs and the pump-is not operating.

4; A lift trailer comprising a frame assembly, supporting wheel-assemblieson opposite sides of thev frame assembly, coacting formations on the frameand wheel assemblies providing for relative guided movements of the frame assembly, spring means carried by each wheel assembly, bars on the frame assembly movablein-one direction to' rest on` the springmeans to support the frame'- assembly. thereon= and inthe opposite direction to clear the spring means and permit descent, ofV the framel assembly, and stabilizing` means for preventing canting of the frame assembly during its vertical movements comprising a cable having its endsl attached to the' wheel assemblies and extending transversely of and around spaced rollers mounted on the frame, ay partl of the cable passing around a roller positionedrv at one side ofv the frame above the spaced rollers.

5. A: lift trailer comprising a frame assembly, supporting Wl'ieel` assemblies on opposite sides of the frame assembly, coacting formations on the frame and wheel assemblies providing for relative guided movements off the frame assembly, spring means. carried by eachr wheel assembly,

bars entire frame assembly movabl'ein one direc@ tion to" rest on the spring means` to support the,1`

frame assembly` thereon and' in' the opposite" direction toV clear the springineans and permitdescent ot the' trame assembly, and'I stabilizing means for preventing canting of? the frame as-a sembly during its vertical movements comprising a pair' oit cables each'- having' its ends attached to; the Wlieeli assemblies andy extending' transversely oi' and` around spaced rollers mounted on tiie frame, a partv of each cable passing arourid a roller positioned` at one side of tlief frame above the associated spaced rollers and tlieA` h'iglier rollers being locatedl on opposite sides of the frame.

6. A lift trailer comprisir'i'gv a trarne' assembly, supporting wheel assemblies' on opposite sides of the frame assembly, coacting formations on tbe` frame and' wheel' assembliesprovidiiig for relative guided movements'- oi' the frame assembly,- springmeans carried: by eacli wheel assembly,V bars cn tlie'frame assembly movable in one directien to r-est on tile spring means to support the frame assembly thereon'- and in tile opposite 1 direction tol clear tlie spring means and permit descent ci the frame' assembly, and a hydraulic system including apump, cooperating' pistons and; cylinders interposed between tneframe and wheel assembliesl and; relatively operable to raise the'irame assemblyr totransporting position, and throttle meansV for controlling tlief gravit-y descent ot tbe frame assembly whenl the bars are freed' of tbev spring' means and the pump is" not operating.

7. A lift trailer comprising! aframe assembly, supporting Wheel assembliesV on' opposite sides and intermediate'the-endsof tbe frame assembly, coaet'ing formations on' the-frame and yilieel as# semblies providing for relative guided movements of the frame assembly, parts carried; by their-ame and wheel assemblies, respectively, and relativelyI movable between positions in which the parts are engaged' to support thefra'me. assembly on the wheel' assemblies' and in which4 the parts-are diseng-:aged' to'permitY descent oi the frame assembly relative to the wheel assemblies, andc stabilizing meansv forv preventing cantin'g" ofv the frame assembly during its vertical' movements comprising a cable' having its ends attached' to they wlieelVV assemblies' and' extending transversely' of and around spaced" rollers mounted on oppositesides or thel frame, a part of thel cable passing around a roller positioned at one 'ideof the frameY above tile spacedrollers:

8. Ai lift trailer comprising a frame assembly', supporting wheel assemblies on opposite sides of: tbeA frame assembly, coasting' formations on? the frame and wheelassemblies providing for rela'- tive guided movements of the frameasseinblyi meansv carried byeach-wheel assembly and-de- 2,648,546 9 lo tachably engageable with the frame assembly to References Cited in the le of this patent support the same, and stabilizing means for pre- UNITED STATES PATENTS Venting cantmg of the frame assembly durlng its vertical movements comprising a pair of cables Number Name Date each having its ends attached to the Wheel as- 5 1,978,498 Llptm'n Oct' 30 1934 semblies and extending transversely of and 2,002,605 K mcald, J1 May 28, 1935 around spaced rollers mounted on the frame, a 2,475,443 B111 July 5 1949 part of each cable passing around a roller posi- 214801909 Dams. Sept 6J 1949 tioned at one side of the frame above the asso- 214951449 Francis Jan- 24 1950 elated spaced rollers and the higher rollers being 10 215631912 Kemmerer Oct- 24 1950 located on opposite sides of the frame. 215321896 Acton Jan 15, 1952 FOREIGN PATENTS JOHN C, FAIKENHAGEN. Number Country Date 766,917 France Apr. 23, A1934; 

